ADC08161 National Semiconductor, ADC08161 Datasheet - Page 6

• Manufacturer Part Number: ADC08161
• Description: 500 ns A/D Converter with S/H Function and 2.5V Bandgap Reference
• Manufacturer: National Semiconductor

Bandgap Reference Electrical Characteristics
(Continued)
Note 2: All voltages are measured with respect to the GND pin, unless otherwise specified.
+
<
>
Note 3: When the input voltage (V
) at any pin exceeds the power supply voltage (V
GND or V
V
), the absolute value of the current at that pin should be
IN
IN
IN
limited to 5 mA or less. The 20 mA package input current specification limits the number of pins that can exceed the power supply boundaries with a 5 mA current
limit to four.
Note 4: The power dissipation of this device under normal operation should never exceed 875 mW (Quiescent Power Dissipation + TTL Loads on the digital outputs).
Caution should be taken not to exceed absolute maximum power rating when the device is operating in a severe fault condition (e.g., when any input or output ex-
ceeds the power supply). The maximum power dissipation must be derated at elevated temperatures and is dictated by T
(maximum junction temperature),
JMAX
JA
= (T
(package junction to ambient thermal resistance), and T
(ambient temperature). The maximum allowable power dissipation at any temperature is PD
A
max
JMAX
= 105˚C and
= 85˚C/W.
− T
)/
or the number given in the Absolute Maximum Ratings, whichever is lower. For this device, T
A
JA
JMAX
JA
Note 5: See AN-450 “Surface Mounting Methods and Their Effect on Product Reliability” for other methods of soldering surface mount devices.
Note 6: Human body model, 100 pF discharged through a 1.5 k
resistor.
Note 7: Typicals are at 25˚C and represent most likely parametric norm.
Note 8: Limits are guaranteed to National’s AOQL (Average Output Quality Level).
Note 9: Total unadjusted error includes offset, full-scale, and linearity errors.
+
Note 10: Two on-chip diodes are tied to each analog input and are reversed biased during normal operation. One is connected to V
and the other is connected to
+
GND. They will become forward biased and conduct when an analog input voltage is equal to or greater than one diode drop above V
or below GND. Therefore,
+
= 4.5V. Analog inputs with magnitudes equal to 5V can cause an input diode to conduct, especially at elevated tem-
caution should be exercised when testing with V
peratures. This can create conversion errors for analog signals near full-scale. The specification allows 50 mV forward bias on either diode; e.g., the output code will
be correct as long as the analog input signal does not exceed the supply voltage by more than 50 mV. Exceeding this range on an unselected channel will corrupt
the reading of a selected channel. An absolute analog input signal voltage range of 0V
V
5V can be achieved by ensuring that the minimum supply voltage ap-
IN
+
plied to V
is 4.950V over temperature variations, initial tolerance, and loading.
Note 11: Off-channel leakage current is measured on the on-channel selection.
www.national.com
6